tools/gn/bin/gyp_flag_compare.py

   1 #!/usr/bin/env python
   2
   3 # Copyright 2014 The Chromium Authors. All rights reserved.
   4 # Use of this source code is governed by a BSD-style license that can be
   5 # found in the LICENSE file.
   6
   7 """Given the output of -t commands from a ninja build for a gyp and GN generated
   8 build, report on differences between the command lines."""
   9
  10
  11 import os
  12 import shlex
  13 import subprocess
  14 import sys
  15
  16
  17 # Must be in src/.
  18 os.chdir(os.path.join(os.path.dirname(__file__), '..', '..', '..'))
  19
  20
  21 g_total_differences = 0
  22
  23
  24 def FindAndRemoveArgWithValue(command_line, argname):
  25   """Given a command line as a list, remove and return the value of an option
  26   that takes a value as a separate entry.
  27
  28   Modifies |command_line| in place.
  29   """
  30   if argname not in command_line:
  31     return ''
  32   location = command_line.index(argname)
  33   value = command_line[location + 1]
  34   command_line[location:location + 2] = []
  35   return value
  36
  37
  38 def MergeSpacedArgs(command_line, argname):
  39   """Combine all arguments |argname| with their values, separated by a space."""
  40   i = 0
  41   result = []
  42   while i < len(command_line):
  43     arg = command_line[i]
  44     if arg == argname:
  45       result.append(arg + ' ' + command_line[i + 1])
  46       i += 1
  47     else:
  48       result.append(arg)
  49     i += 1
  50   return result
  51
  52
  53 def NormalizeSymbolArguments(command_line):
  54   """Normalize -g arguments.
  55
  56   If there's no -g args, it's equivalent to -g0. -g2 is equivalent to -g.
  57   Modifies |command_line| in place.
  58   """
  59   # Strip -g0 if there's no symbols.
  60   have_some_symbols = False
  61   for x in command_line:
  62     if x.startswith('-g') and x != '-g0':
  63       have_some_symbols = True
  64   if not have_some_symbols and '-g0' in command_line:
  65     command_line.remove('-g0')
  66
  67   # Rename -g2 to -g.
  68   if '-g2' in command_line:
  69     command_line[command_line.index('-g2')] = '-g'
  70
  71
  72 def GetFlags(lines):
  73   """Turn a list of command lines into a semi-structured dict."""
  74   flags_by_output = {}
  75   for line in lines:
  76     # TODO(scottmg): Hacky way of getting only cc for now.
  77     if 'clang' not in line:
  78       continue
  79
  80     command_line = shlex.split(line.strip())[1:]
  81
  82     output_name = FindAndRemoveArgWithValue(command_line, '-o')
  83     dep_name = FindAndRemoveArgWithValue(command_line, '-MF')
  84
  85     NormalizeSymbolArguments(command_line)
  86
  87     command_line = MergeSpacedArgs(command_line, '-Xclang')
  88
  89     defines = [x for x in command_line if x.startswith('-D')]
  90     include_dirs = [x for x in command_line if x.startswith('-I')]
  91     dash_f = [x for x in command_line if x.startswith('-f')]
  92     warnings = [x for x in command_line if x.startswith('-W')]
  93     cc_file = [x for x in command_line if x.endswith('.cc') or
  94                                           x.endswith('.c') or
  95                                           x.endswith('.cpp')]
  96     if len(cc_file) != 1:
  97       print 'Skipping %s' % command_line
  98       continue
  99     assert len(cc_file) == 1
 100     others = [x for x in command_line if x not in defines and \
 101                                          x not in include_dirs and \
 102                                          x not in dash_f and \
 103                                          x not in warnings and \
 104                                          x not in cc_file]
 105
 106     # Filter for libFindBadConstructs.so having a relative path in one and
 107     # absolute path in the other.
 108     others_filtered = []
 109     for x in others:
 110       if x.startswith('-Xclang ') and x.endswith('libFindBadConstructs.so'):
 111         others_filtered.append(
 112             '-Xclang ' +
 113             os.path.join(os.getcwd(),
 114                          os.path.normpath(
 115                              os.path.join('out/gn_flags', x.split(' ', 1)[1]))))
 116       elif x.startswith('-B'):
 117         others_filtered.append(
 118             '-B' +
 119             os.path.join(os.getcwd(),
 120                          os.path.normpath(os.path.join('out/gn_flags', x[2:]))))
 121       else:
 122         others_filtered.append(x)
 123     others = others_filtered
 124
 125     flags_by_output[cc_file[0]] = {
 126       'output': output_name,
 127       'depname': dep_name,
 128       'defines': sorted(defines),
 129       'include_dirs': sorted(include_dirs),  # TODO(scottmg): This is wrong.
 130       'dash_f': sorted(dash_f),
 131       'warnings': sorted(warnings),
 132       'other': sorted(others),
 133     }
 134   return flags_by_output
 135
 136
 137 def CompareLists(gyp, gn, name, dont_care_gyp=None, dont_care_gn=None):
 138   """Return a report of any differences between gyp and gn lists, ignoring
 139   anything in |dont_care_{gyp|gn}| respectively."""
 140   global g_total_differences
 141   if not dont_care_gyp:
 142     dont_care_gyp = []
 143   if not dont_care_gn:
 144     dont_care_gn = []
 145   output = ''
 146   if gyp[name] != gn[name]:
 147     gyp_set = set(gyp[name])
 148     gn_set = set(gn[name])
 149     missing_in_gyp = gyp_set - gn_set
 150     missing_in_gn = gn_set - gyp_set
 151     missing_in_gyp -= set(dont_care_gyp)
 152     missing_in_gn -= set(dont_care_gn)
 153     if missing_in_gyp or missing_in_gn:
 154       output += '  %s differ:\n' % name
 155     if missing_in_gyp:
 156       output += '    In gyp, but not in GN:\n      %s' % '\n      '.join(
 157           sorted(missing_in_gyp)) + '\n'
 158       g_total_differences += len(missing_in_gyp)
 159     if missing_in_gn:
 160       output += '    In GN, but not in gyp:\n      %s' % '\n      '.join(
 161           sorted(missing_in_gn)) + '\n\n'
 162       g_total_differences += len(missing_in_gn)
 163   return output
 164
 165
 166 def Run(command_line):
 167   """Run |command_line| as a subprocess and return stdout. Raises on error."""
 168   return subprocess.check_output(command_line, shell=True)
 169
 170
 171 def main():
 172   if len(sys.argv) != 2 and len(sys.argv) != 3:
 173     print 'usage: %s gyp_target gn_target' % __file__
 174     print '   or: %s target' % __file__
 175     return 1
 176
 177   if len(sys.argv) == 2:
 178     sys.argv.append(sys.argv[1])
 179
 180   print >>sys.stderr, 'Regenerating...'
 181   # Currently only Release, non-component.
 182   Run('gn gen out/gn_flags --args="is_debug=false is_component_build=false"')
 183   os.environ.pop('GYP_DEFINES', None)
 184   Run('python build/gyp_chromium -Goutput_dir=out_gyp_flags -Gconfig=Release')
 185   gn = Run('ninja -C out/gn_flags -t commands %s' % sys.argv[2])
 186   gyp = Run('ninja -C out_gyp_flags/Release -t commands %s' % sys.argv[1])
 187   all_gyp_flags = GetFlags(gyp.splitlines())
 188   all_gn_flags = GetFlags(gn.splitlines())
 189   gyp_files = set(all_gyp_flags.keys())
 190   gn_files = set(all_gn_flags.keys())
 191   different_source_list = gyp_files != gn_files
 192   if different_source_list:
 193     print 'Different set of sources files:'
 194     print '  In gyp, not in GN:\n    %s' % '\n    '.join(
 195         sorted(gyp_files - gn_files))
 196     print '  In GN, not in gyp:\n    %s' % '\n    '.join(
 197         sorted(gn_files - gyp_files))
 198     print '\nNote that flags will only be compared for files in both sets.\n'
 199   file_list = gyp_files & gn_files
 200   files_with_given_differences = {}
 201   for filename in sorted(file_list):
 202     gyp_flags = all_gyp_flags[filename]
 203     gn_flags = all_gn_flags[filename]
 204     differences = CompareLists(gyp_flags, gn_flags, 'dash_f')
 205     differences += CompareLists(gyp_flags, gn_flags, 'defines')
 206     differences += CompareLists(gyp_flags, gn_flags, 'include_dirs')
 207     differences += CompareLists(gyp_flags, gn_flags, 'warnings', dont_care_gn=[
 208         # More conservative warnings in GN we consider to be OK.
 209         '-Wendif-labels',
 210         '-Wextra',
 211         '-Wsign-compare',
 212         ])
 213     differences += CompareLists(gyp_flags, gn_flags, 'other')
 214     if differences:
 215       files_with_given_differences.setdefault(differences, []).append(filename)
 216
 217   for diff, files in files_with_given_differences.iteritems():
 218     print '\n'.join(sorted(files))
 219     print diff
 220
 221   print 'Total differences:', g_total_differences
 222   # TODO(scottmg): Return failure on difference once we're closer to identical.
 223   return 0
 224
 225
 226 if __name__ == '__main__':
 227   sys.exit(main())